2009 Hummer H2 CONVERSION Duramax Diesel & Allison transmission. This H2 is ready to ROCK n ROLL, it is truly 1 of a kind. 6.6 Liter LMM Duramax Diesel Engine. There are too many items to list on here that I have done, for example, biggest and best alternator, 2 batteries, with a battery cut off switch. External plugs for battery chargers. Upgraded fuse box. Just a lot of little things.